In mass production of contact lenses, specifically so-called disposable lenses, a large number of contact lenses must be manufactured in a relatively short period of time. In a preferred method of mass production, a starting material, e.g., a prepolymer solution containing water, is introduced into a female mold half, the casting mold is closed by the respective male mold half and then the starting material is polymerized and/or crosslinked photometrically with the help of UV light. The mold halves mask the UV light in the respective areas which are outside of the areas required for contact lens production. Cyclic mass production of contact lenses is described in WO 98/42497, for example. Suitable polymers formed by photochemical polymerization of suitable prepolymers include polymers based on polyvinyl alcohols (PVA) or silicone hydrogels (SiHy) as well as based on polyethylene glycols (PEG).
After polymerization and/or crosslinking and then opening the casting molds, the contact lenses must be removed from the mold halves and brought to the next production station, e.g., the coating station, the cleaning station or the inspection station. To do so, it is typical to use vacuum gripper, which are robot-controlled and with the help of a vacuum grip the contact lenses with suction, convey them further and then deposit them at the desired destination. So-called mechanical tweezers grippers are also known. Disadvantages of most of these mechanical approaches include not only the high cost of the robot systems but also the mechanical stress and the risk of damage to the contact lenses. For example, silicone hydrogels (SiHy) are used for the production of extremely oxygen-permeable contact lenses; they may adhere so tightly to the mold half that mechanical transport tools are unable to easily lift the contact lenses up from the mold halves and transport them. It may also happen that after the contact lenses have been lifted, they cannot be removed from the grippers easily.